wicker and president obama received. >> more tests are being done on the letters. more details now about the poison ricin. it comes from the bean of the caster oil plant, and it is deadliest when inhaled. it could be used to kill an individual, but would not work for a large group of people, and does not pass from person to person. there is only one known assassination using ricin. in 1978, a bulgarian dissident. >>> sabotage in the south bay. new details on the attacks on two crucial utilities. why investigators think they were you kids should count yourselves lucky. we didn't have u-verse back in my day. you couldn't just... guys... there you are. you know you couldn't just pause a show in one room, then... where was i... you couldn't pause a show in one room then start playing it in another. and...i'm talking to myself... [ male announcer ] call to get u-verse tv for just $19 a month for 2 years with qualifying bundles. rethink possible. >>> all in all, this was a pretty shameful day for washington, but this effort is not over. >> a visibly angry president obama